MARTINEZ -- A serial child molester could spend the rest of his life in prison following a jury trial verdict Tuesday.

After about three hours of deliberations, a Contra Costa County jury convicted Oakland resident Ronald Heartsill, 58, of two counts of lewd and lascivious acts with a child under age 14 for molesting a 4-year-old girl in Martinez last year.

Heartsill faces up to 85 years to life in prison for the crimes because of his history of sexually abusing children, said deputy district attorney Ryan Wagner. Heartsill was first convicted of felony charges in 1983 for molesting two boys in San Pablo, and then again in 1990 for molesting a girl in Clayton. Heartsill was also convicted of misdemeanor child molestation for an incident involving a 16-year-old boy in Martinez in 2000.

"He has a demonstrated history of taking advantage of vulnerable people in his life," Wagner said.